A heat exchanger includes a plurality of tubes and fins, an inlet tank, and an outlet tank. The inlet tank and the outlet tank are in fluid communication with the plurality of tubes through inlets and outlets formed at respective ends of the tubes. Thermal fluid in the inlet tank flows into the tubes through the inlets and the thermal fluid flows through the tubes while exchanging heat with air. Then, the thermal fluid flows into the outlet tank through the outlets after the heat exchange.
Generally, a flow rate of the thermal fluid for each tube may influence heat exchanging performance of a heat exchanger. For example, when the flow rates of the thermal fluid flowing through tubes are low, the heat exchanging performance may decrease, whereas when the flow rates of the thermal fluid is high, the heat exchanging performance may increase.